Multi-antenna interferometers determine a direction of arrival of a signal using a difference between a phase of the signal as received by a reference antenna and a phase of the signal as received by at least one other antenna. Many interferometers perform phase detection using phase data received via parallel channels. Transmitting phase data via a single channel rather than parallel channels is beneficial in various situations, such as when the interferometer is installed in an existing system (e.g., retrofitted in an aircraft). Transmitting interferometer data via a single channel potentially reduces the size, weight, power, and cost requirements of interferometer electronics and direction finding systems.